Would any of the top-finishing engines be REALLY USABLE in a weekend fun car (that maybe sees some limited street duty) or are they compromised to the point they're really only good for a few dyno pulls? i.e. a purpose-built dyno queen engine?

I gotta admit that a REAL 600+HP 360ci N/A small block is a feat far beyond my capability. If I ever came into some money and wanted a real a$$-kicker the thought of placing a call to one of these shops has crossed my mind. But would I be getting the same thing that actually hits the dyno in competition or a watered-down "sanitized for your protection" version?

 

I depends. The intent of the competition is to build a "street" engine which can be duplicated. That being said, the idea of each entrant is to WIN. IMO, that means taking advantage of all the rules. I'm pretty sure some folks might push static or dynamic CR's to the point that 92 octane barely is enough. You could just run better gas on the street.

Also, on the positive side, it's probably difficult to fully load an EM engine on a street car at 2500 and only allow it to accelerate at 300 rpm per second, except maybe in top gear, which you probably wouldn't do anyway. On the negative side, EM engines are designed for 6500 max rpm, with a few hundred rpm overrun. Most pull so strongly @ 6500, and may have a fairly flat power peak that you would very likely try to wind it to 7+. That might require more spring pressure than the engine was built with and that could cause problems. Winning EM engines don't have any more of anything, except maybe component strength without compromising weight, than they need. IMO, top rpm might be the biggest problem.

The other thing is cost. You could buy an ex-EM engine for maybe $15,000, but to duplicate a winning or placing one, with all the coatings, etc. might easily top $20,000. Even then, the builder would probably suggest changes (like valve springs) to help it live on the street. Some of the little, but perhaps costly things could be eliminated with only a few percent power loss. Of course, that fraction of a % won the 2002 contest!


Bottom line: IMO any high end race engine, dyno or track, would not be optimum for use in a very different enviornment, like a weekend fun car. EM engines might be close, however if you kept within their design rev range.

There are a few for sale, if you fall into that $.

 

A few for sale, lol well you know one that is.

Our old 365 with 570hp and 535 ft lbs would be an awesome driver. A 214/224 cam is not very crazy and it's one change in the distributor to get the timign curve street gas friendly. That ones for sale for about 1/2 of what it would cost to build from scratch.

As the old man said, if you want a watered down version you can get one, if you want the exact copy or one of the ones from the contest you can get one of those too.

IMHO my goal is always to win, but with that anything I would build for the contest would be a good street car engine on top of it all. Not something grandma would drive but something you could drive on the street without problems. Building a motor to run in the 2500-6500 rpm range is really what street cars do, most times I build motors that have a much narrower and less street friendly range than that and they are street cars.

Bret

 

Thanks to both of the SStrokers here for responding.

Good point about the valve springs and compression ratio.

My main concern when I posted was probably more about compression ratio and component strength. Having built a few street motors, my experience is that you can get away with some very high compression ratios FOR A SHORT TIME. Once you put some hours on them (not many, in fact- 6 hours is plenty on the street idling, tooling around town) carbon and such builds up in the chambers and piston faces and the motor goes bang, especially if it's built with lightweight components. 11:1 is not someplace I go often for that reason, unless I've got a fairly large cam in it.

 

FWIW, on Bret's EM 365, static CR was over 11.5, with a very high dynamic. That sounds like a recipe for disaster with 92 octane, but on WOT dyno pulls from 2500, and advance for best power, a knock sensor only sensed minor knock just about 3000, for less than one second a pull. When the engine was torn down there was absolutely no signs of any problems. Chamber, piston crown and squish were all pretty well designed, and he ran it a tad rich. Not pig rich, maybe just piglet rich.

The 92 octane gas provided by the EM contest had a .735 SG, and seemed at least as knock resistant as Sunoco 94. Of course there is octane and there is octane. The pump number is an average of Research and Motor octane numbers. One favors part throttle and one favors WOT. I guess you could mix a batch of 92 that favored the WOT performance and still legally call it 92. No one fessed up to doing that, but the 11+:1 engines seemed to do wellon it.

By bringing the timing in a few hundred rpm later, the knock disappeared, but the under 3500 rpm torque was off a few lb-ft. I think that's what Bret suggests for running that engine on the street.

As far as component strength, I am familiar with Bret's engine. The parts were more than strong enough. His idea was to do it right, but keep the rotating parts reasonably light. For example, he used a GMPP CNC bowtie block with 8620 main caps. Even the front and rear caps are CNCd from 8620 and all have 4 bolts/studs. It's rated for a 4.16 bore: his was 4.075. 570-600 hp @6500 isn't even making that block work up a sweat.

Not saying that everyone went that way, but some did.